The code was pretty easy, and if people like this feature, I can make a Toolserver utility for Wikimedia lists basing of that. :)
Is there any way you could merge the counts for people with multiple email addresses? Some way for people to enter addresses into a form to say they are the same person (and some way for others to review it)? For example, the top poster looks like it's actually Anthere, but she posts under both her pseudonym and real name, so Ray ends up being on top.